Wasn't Crying Wolf!
It turns out that I wasn't imagining Moore FD on the DPS System after all!
At 07:06 Moore FD dispatched a fire alarm and it absolutely, positively was simulcast on the Norman site of the DPS system. I still show it as TGID 51696 and since the talkgroup is the same as it was last time, I suspect that it is a good id.
I got to thinking that with only four voice channels available on the Norman site and with Moore PD, Norman PD, CCSO, and often Shawnee PD on the site, along with the normal OHP traffic, they might keep that link turned off during the high radio traffic periods.